This invention relates to a method of piling a cast-in-place concrete pile widely used as a foundation in construction works and an apparatus for carrying out the method.
There have been various methods of piling cast-in-place piles such as Benote piling method, reverse piling method, earth drill piling method, deep foundation piling method and the like. The method according to the invention comes within the earth drill piling method.
In the earth drill piling method, excavating is directly effected by means of a rotary bucket without protecting the walls of excavated holes from crumbling. In the event that walls of an excavated hole require to be prevented from falling down, muddy water as bentonite suspension is used.
In excavating with the rotary bucket, after the bucket has been filled with excavated earth and sand, the bucket is once pulled up to exhaust the earth and sand out of the excavated hole, and thereafter the bucket is again inserted into the hole. Such an operation is repeated many times. Therefore, the time for the excavating work becomes longer by the time required for exhausting the excavated earth and sand in the bucket.
In case that muddy water such as bentonite suspension or the like is used for preventing the walls of the hole from crumbling, as the excavated earth and sand will mixed with the bentonite suspension to produce so-called industrial waste. If the industrial waste is not properly treated, it will cause an environmental pollution.